<?php
namespace App\Http\Controllers\Api\Wechat;

class JSSDK
{
    private $appId;
    private $appSecret;

    public function __construct()
    {
        $this->appId = config('services.weixin.client_id');
        $this->appSecret = config('services.weixin.client_secret');
    }

    //获取access_token
    public function getAccessToken()
    {
        // access_token 应该全局存储与更新，以下代码以写入到文件中做示例
        $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={$this->appId}&secret={$this->appSecret}";
        $res = $this->getJson($url);
        return $res['access_token'];
    }

    //创建随机字符串
    private function createNonceStr($length = 16) {
        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        $str = "";
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }

    //获取jsapi_ticket
    public function getJsApiTicket()
    {
        $accessToken = $this->getAccessToken();
        $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token={$accessToken}&type=jsapi";
        $res = $this->httpGet($url);
        return $res['ticket'];
    }


    //curl发送get请求
    public function getJson($url)
    {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        $output = curl_exec($ch);
        curl_close($ch);
        return json_decode($output, true);   //数组
    }

    //curl发送get请求   获取ticket
    private function httpGet($url)
    {
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_URL, $url);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        // curl_setopt($curl, CURLOPT_TIMEOUT, 500);
        // 为保证第三方服务器与微信服务器之间数据传输的安全性，所有微信接口采用https方式调用，必须使用下面2行代码打开ssl安全校验。
        // 如果在部署过程中代码在此处验证失败，请到 http://curl.haxx.se/ca/cacert.pem 下载新的证书判别文件。
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);
        $res = curl_exec($curl);
        // var_dump($res);
        curl_close($curl);
        return json_decode($res, true);  //数组
    }

    //获取签名包
    public function getSignPackage()
    {
        $jsapiTicket = $this->getJsApiTicket();
        // 注意 URL 一定要动态获取，不能 hardcode.
        $protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
        $url = "$protocol$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
        $timestamp = time();
        $nonceStr = $this->createNonceStr();
        // 这里参数的顺序要按照 key 值 ASCII 码升序排序
        $string = "jsapi_ticket={$jsapiTicket}&noncestr={$nonceStr}&timestamp={$timestamp}&url={$url}";
        $signature = sha1($string);
        $signPackage = array(
            "appId"   => $this->appId,
            "nonceStr" => $nonceStr,
            "timestamp" => $timestamp,
            "url"    => $url,
            "signature" => $signature,
            "rawString" => $string
        );
        return $signPackage;
    }
}
